1998 World Junior Championships in Athletics – Men's 400 metres

Final

31 July

Rank	Name	Nationality	Time	Notes
	Nduka Awazie	Nigeria	45.54
	Casey Vincent	Australia	45.55
	Fawzi Al-Shammari	Kuwait	45.89
4	Marc-Alexander Scheer	Germany	45.91
5	Simon Pierre	Trinidad and Tobago	46.22
6	Andrew Pierce	United States	46.30
7	Alloy Wilson	United Kingdom	46.64
8	Tony Berrian	United States	47.30

Semifinals

29 July

Semifinal 1

Rank	Name	Nationality	Time	Notes
1	Andrew Pierce	United States	46.32	Q
2	Fawzi Al-Shammari	Kuwait	46.40	Q
3	Marc-Alexander Scheer	Germany	46.57	q
4	Kim Jae-Da	South Korea	46.94
5	Amin Goma'a	Egypt	47.60
6	Xu Zizhou	China	47.62
7	David Naismith	United Kingdom	47.73
8	Liam Card	Canada	48.03

Semifinal 2

Rank	Name	Nationality	Time	Notes
1	Casey Vincent	Australia	46.49	Q
2	Simon Pierre	Trinidad and Tobago	46.66	Q
3	Alloy Wilson	United Kingdom	46.69	q
4	Ousmane Niang	Senegal	46.88
5	Ruwen Faller	Germany	46.96
6	Fernando Augustin	Mauritius	47.42
7	Evanson Ndungu	Kenya	47.51
8	Przemyslaw Dunaj	Poland	48.03

Semifinal 3

Rank	Name	Nationality	Time	Notes
1	Nduka Awazie	Nigeria	45.90	Q
2	Tony Berrian	United States	46.56	Q
3	Tom Coman	Ireland	46.82
4	Masayuki Okusako	Japan	47.36
5	Daniel Batman	Australia	47.41
6	Hamdan Al-Bishi	Saudi Arabia	47.47
7	Luys Freitas	Portugal	48.11
8	William Hernández	Venezuela	48.77

Heats

28 July

Heat 1

Rank	Name	Nationality	Time	Notes
1	Nduka Awazie	Nigeria	46.76	Q
2	Ousmane Niang	Senegal	47.01	Q
3	Fawzi Al-Shammari	Kuwait	47.42	Q
4	Sanjay Ayre	Jamaica	47.51
5	Michał Węglarski	Poland	47.57
6	Casper Pule	Solomon Islands	49.65
7	Charles Shaw	Liberia	51.32

Heat 2

Rank	Name	Nationality	Time	Notes
1	Andrew Pierce	United States	46.51	Q
2	Tom Coman	Ireland	47.14	Q
3	Daniel Batman	Australia	47.17	Q
4	David Naismith	United Kingdom	47.47	q
5	Ranga Wimalawansa	Sri Lanka	47.55
6	Mohamed Bezegrari	Algeria	49.39

Heat 3

Rank	Name	Nationality	Time	Notes
1	Hamdan Al-Bishi	Saudi Arabia	46.93	Q
2	Evanson Ndungu	Kenya	47.04	Q
3	Ruwen Faller	Germany	47.08	Q
4	Fernando Augustin	Mauritius	47.31	q
5	Paul Oppermann	Ireland	47.81
6	Alexander Petrov	Bulgaria	48.72
7	Isaac Yaya	Tahiti	50.10

Heat 4

Rank	Name	Nationality	Time	Notes
1	Alloy Wilson	United Kingdom	46.81	Q
2	Xu Zizhou	China	46.92	Q
3	Simon Pierre	Trinidad and Tobago	46.99	Q
4	Masayuki Okusako	Japan	47.37	q
5	Ahmed Torkhani	Tunisia	48.08
6	Damian Spector	Argentina	48.35
7	Harmon Harmon	Cook Islands	51.82

Heat 5

Rank	Name	Nationality	Time	Notes
1	Casey Vincent	Australia	46.87	Q
2	Luys Freitas	Portugal	47.66	Q
3	William Hernández	Venezuela	47.81	Q
4	Takahiko Yamamura	Japan	47.95
5	Andrea Barberi	Italy	47.96
6	Ryad Cheragui	Algeria	49.77

Heat 6

Rank	Name	Nationality	Time	Notes
1	Kim Jae-Da	South Korea	47.17	Q
2	Marc-Alexander Scheer	Germany	47.27	Q
3	Przemyslaw Dunaj	Poland	48.08	Q
4	Marc Reuter	Luxembourg	48.28
5	Vicente Erut	Argentina	49.14
6	Edward Grech	Malta	51.21

Heat 7

Rank	Name	Nationality	Time	Notes
1	Tony Berrian	United States	47.06	Q
2	Amin Goma'a	Egypt	47.57	Q
3	Liam Card	Canada	47.71	Q
4	Tshepo Thobelangope	South Africa	47.90
5	Hicham Mihjane	Morocco	48.03
6	Clement Abai	Papua New Guinea	48.41
7	Troy Wickham	Barbados	48.65

According to an unofficial count, 46 athletes from 37 countries participated in the event.